Female eye affected by keratoconus, or conical cornea, which could be corrected by a special light-activated biomaterial
Eye of a woman affected by keratoconus, or conical cornea [Credit: sruilk/Getty Images].

A specially designed biomaterial that can be activated by low-energy blue light could help reshape damaged corneas and at least partially overcome the need for donor eye tissue.

The material, designed by researchers based at the University of Montréal and the University of Ottawa, is composed of short peptides, chondroitin, and hyaluronic acid and can change into a hydrogel when exposed to pulses of blue light.

“Our technology is a leap in the field of corneal repair. We are confident this could become a practical solution to treat patients living with diseases that negatively impact corneal shape and geometry, including keratoconus,” said co-lead investigator Emilio Alarcon, an associate professor at the University of Ottawa Faculty of Medicine, in a press statement.

Many thousands of people suffer from diseases of the cornea in the eye. Transplantation of corneal tissue from donors is currently the only real option for the advanced stage of diseases such as keratoconus, where people’s vision is damaged due to thinning corneas, but there is not enough donor tissue available for those who need it.

Biomaterial based alternatives, such as solid corneal implants made from recombinant human collagen, provide an alternative to donor transplants, but also require invasive surgery. An injectable material that becomes more solid once in the correct position is attractive as it could take the place of donor tissue and be inserted into the eye in a minimally invasive manner.

As reported in the journal Advanced Functional Materials, the researchers first tested different formulations of material containing varying amounts of hyaluronic acid methacrylate, chondroitin sulfate methacrylate, and gelatin methacrylate, as well as short peptides, with varying light intensities.

“Chondroitin and hyaluronic acid were incorporated into formulations as they have been shown to promote corneal wound healing and have already been approved for use in ophthalmic viscosurgical devices such as Viscoat in the clinic,” write the authors.

Once the team perfected the material, and were able to activate it at low blue light levels (8.5 mW cm−2) to prevent any blue-light related toxicity, the material was tested in rat corneas. The material was stable and did not appear to cause significant inflammation or neovascularization.

“Our material was engineered to harvest the blue light energy to trigger the on-the-spot assembling of the material into a cornea-like structure… We anticipate our material will remain stable and be non-toxic in human corneas,” said co-lead author Alarcon.

Next steps for the material will involve testing it in larger animal models before moving into human trials, as well as obtaining a patent for the technology.

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